Gyratory crusher with setting indicator

ABSTRACT

A gyratory crusher is disclosed having a vertical post assembly with a crushing head mounted on top, and the post assembly is slidably supported in a lower frame. An overhanging concave ring is supported in a fixed position around the crushing head by an upper frame. The post assembly includes a hydraulically operated piston for raising and lowering the crushing head relative to the concave ring and the lower frame includes a cylinder supporting the piston. The piston has a downwardly pointed taper defining a cam surface. A linear variable differential transformer is connected to the cylinder and has a movable core which is slidably biased to horizontally project through the cylinder and engage the cam surface of the piston to move inwardly upon upward movement of the piston and be pushed outwardly by the cam surface upon downward movement of the piston. The movement of the core provides an electrical output signal that indicates the position of the crushing head carried by the piston, relative to the concave ring.

United States Patent I [7 Inventor Robert J. Pollak Primary Examiner-Donald G. Kelly Milwaukee, s- Attorneys-Arthur M. Streich, Robert B. Benson and John P. [21] Appl. No. 877,966 Hing? g} [22] Filed Nov. 19, 1969 [45] Patented Aug. 17, 1971 [73] Assignee Allis-Chalmers U v.

Milwaukee ABSTRACT: A gyratory crusher is disclosed having a vertical W post assembly with a crushing head mounted on top, and the I 54] GYRATORY CRUSHER WIT" SET-"N6 post assembly is slidably supported in a lower frame. An over- INMCATOR hanging concave ring is supported in a fixed position around 8 Claim! 1 Drhwlns m the crushing head by an upper frame. The post assembly mcludes a hydraulically operated piston for raising and lowering Us. .1 n" the crushing head relative to the concave ring and the lower 241/286 frame includes a cylinder supporting the piston. The piston Inthas a downwardly Pointed taper defining a cam surface A [50] Field of Search 241/37, "near variable diff ti l transformer is connected to the 290 cylinder and has a movable core which is slidably biased to horizontall ro'ect throu h the c linder and en a e the cam [56] Rekrencs C'ted surface of h e p iston to nEove imzardly upon u aw ard move- UNITED STATES PATENTS ment of the piston and be pushed outwardly by the cam sur- 2,941,732 6/1960 Cross 241/101 face upon downward movement of the piston. The movement 3,133,706 5/1964 Mertz 241/37 X of the core provides an electrical output signal that indicates 3,133,707 5/1964 Zimmerman 241/213 X the position of the crushing head carried by the piston, relative 3,328,888 7/1967 Gieschen 241/213 X to the concave ring.

' in U.S. Pat. No. 2,941,732.

BACKGROUNDQFTHE INVENTION 1. Field of the Invention This invention relates generally to ore-crushing machines having an annular bowl and a cone-shaped crushing head which gyrates within the bowl and about a generally vertical axis, to crush material passing between the bowl and the crushing head, and in particular to such machines as provide for relative movement of the bowl and crushing head along the vertical axis and have means for detecting and indicating the position of the crushing head relative to the bowl while the machine is in continuous operation. I

2. Description of the Prior Art US. Pat. Nos. 2,941,732; 3,078,051; 3,1 17,734; 3,125,303; 3,436,653; 3,436,654 and German Pat. No. 1,254,943 are known to be related to the field of the present invention.

Two of these patents namely US. Pat. 'No. 3,436,653 and US; Pat. No. 3,436,654, disclose electrical systems that indicate crusher openings by measuring capacitance. These systems were found to be affected by weather and did not work well on days of high humidity;

Three of the foregoing patents, namely, US. Pat. Nos. 3,078,051; 3,1 17,734; and 3,125,303; disclose: systems in which the pressure or level of hydraulic'fluid used to support and move a crushing head assembly, is detected to indicate head position. The system that detects the pressure of fluid supporting a head assembly provides a goodmeas'ure of load but not precise head position, because a crushercan be loaded to a particular fluid pressure with the head at different'positions. A fluid level detecting system as disclosed in U.S. Pa t. No..3,l25,303 measures fluid'level in aspecialreservoirprovided for that purpose and the system is not operative to indicate true head position when movement is caused bytramp metal or other overload that causes some of the -fluidito move from the head support mechanism into a resetdevice, usually containing a bladder. If any ofthefluid from'thehead support system moves to the reset device rather than aupr the "fluid moving into the special reservoir, an inaccurate indication-of head position is registered. 7 i I Systems that rely upon fluid pressure or level have not. therefore been widely accepted and those skilled in this art have continued to pursue the development of systems-including a position-detecting probe such as disclosed, for example,

US. Pat. No. 2,941,732 discloses an example of a crusher with an upper end of a head assembly journaled in. abearing carried by a spider assembly spanning atop opening of a conv cave ring surrounding the head, with means mounted ,in the trade as operators were reluctant to acquire accessory :equ'iprnent that increased vertical space requirements for the machine.

SUMMARY OF THE PRESENT INVEN'IION Objects of the present invention include providing for a crusher-having a vertically adjustable head assemblynaposition-indicating system that :can be applied to spiderless crushers aswell as crushers having--aspider,does not add to verticalspace requirements'for such machines, -and=is suitably rugged andreliable, with positive .engagement with a moving portion of the vertically adjustable head assembly.

In a preferred embodiment of a gyratory crusher according --to the present inventiona lower frameincludes 'a'cylinder arranged with a central axis of the cylinder in a vertical position and an end wall enclosing the lower end of the .cylinder. A :piston is "arranged within thecylinder, with a top side of the :piston'in agenerally horizontal plane for carrying thereon the shaft ofaconical crushinghead. The piston has adownwardly tapered portion defining a cam surface. A linear variable differential transformer is connected to the cylinder and has a movable core which is horizontally biased to slidably project through the cylinder and engagethecamsurface of .the piston to move inwardly upon upward movement of the piston and be lpushed outwardlylby thecamsurface upon downward move- .mentofthe piston. The movement of the linear variable differential transformer core provides an electrical output signal tl lat indicates the verticalposition of the gpistonand the crushing -head mountedonttheshaftcarried by the piston.

Other-features and objects of theinventionthat have been I v.attainetlwilltappeartfromthernore detaileddescriptionto-folllowwith reference to an-embodiment of-the present invention shown in the accompanyingdrawing.

BRIEFJDESC'RIPT ION OF THE-DRAWING DESCRIPTION OF THEPREFERRED'EMBODIMENT Thegyratorycrusher shown inthedrawing includes-a lower frame l andan upper frame 2-mounted on the-lower frame, and the "upper'frame carries a concave ring 3. The concave ring'3is carried in afixed pos'itionby bolts 4 which.connect an upper flange 5-.of the upper frame v2,'to lugs 6 whichproject horizontally outward from the outer surface of the ring 3. The lower'frame 1 includes a cylinder arranged with a central axis 1-1 of the 'cylinderin a verticalposition. Acylinder end wall '12 encloses the lower end of cylinder '11 .and defines therethrough'a fluid pressure adm'ittingpassage 13. A vertical crusher post assembly 15 is carried by thelowerframe .-'l. The ,postassenibly l 5 comprises apistonlfl having a'lower surface member "17 which with the cylinder 11' and end wall 12 defines ferential transformer generates an electrical'signal which is used to establish a visual indication of the position of'the head assembly relative to the surrounding bowl structure. Although differential transformers requiredfor such a system were reliable and available, providing such devices inaspiderassembly placed-such devices in a member subjected to impact: blows of relative large pieces of ore being dumped into-the crusher feed opening with many such pieces striking the spider, thus requiring a heavy spider to protect such devices, and of course such a system has no utility at all for application to a spiderless a'fluid pressure expandable chamber 18, that is the vertical dimension of "chamber '18 can be .adjusted by controlling the l'flow of pressure into chamber :18 by suitable means -(not shown). The piston l6 has .a top surface 1.19 for carrying ,thereona stepbearing structure which maybe constructed-accrusher. German Pat. No. 1,254,943 is another example of such a system that requires acrusher to have a spider orother support over the feed opening. Those skilled in this art therefore had considered mounting probe operated devices underneath the hydraulic cylinder whichis below thecone assembly, with a probe or movable core-projectingverticallylupward through a bottom plate of the hydraulic assembly.Such

cording to US. Pat. No. 2,448,936 to C. :C. .VanZandt. .As shownthe step 'bearingstructure includes a:flatwasherlike insert '20 carried :by'the'surface 19 and a step washer v21 ,with a flatilower surface slidable' laterally onthe insert .20. .The-step -washer2-l$has=a concaveupper surface whichcarriesaconvex insert'522 attached to the :bottom -of.a vertical shaft,,23. A crusher'rheadi24 with "a replaceable mantle;25, .is2mounted on the-:upperaendof sha'ft23. The mantle f25tcarri'ed bycrusher head 24 cooperates with .the concave ring 3 to define 't'here'betweenaa-material-'crushingchamber26.

The piston 16 of the .post assembly 15, .is tapered in a downwardly pointed direction. from a .portion' 29 thereof in surface to "surface contact with the cylinder 11, to define a systems also failed toachieve hoped-for acceptance in .the '75 camsurface30'which slopes downwardly,andrinwardlyfrom the portion 29 of piston 16. A linear variable differential transformer 32 (hereinafter referred to as an LVDT) is connected to the outer surface of cylinder 11 by suitable means (not shown). The LVDT 32 has an extended movable core 33 which is horizontally biased to slidably project away from the LVDT 32 and through a bore 34 in cylinder 11 to engage cam surface '30. A suitable conduit 35 may be provided to protect lead wires from the LVDT 32 to a suitable indicating dial 36 calibrated as desired to indicate the position in which piston 16 supports mantle 25 relative to concave ring 3.

The LVDT 32 with its movable core 33 and recording dial 36, is commercially available equipment. U.S. Pat. No. 2,941,782 describes an example of such equipment in detail, identified as being commercially available from the Minneapolis-Honeywell Company of Minneapolis, Minn. Another suitable device is an LVDT manufactured by Ramsey Engineering Co., St. Paul, Minn., and described in a Ramsey Engineering Co. bulletin TDS 20 107.

In the operation of the described crusher, fluid pressure is admitted to the passage 13, from a suitable source (not shown), and the fluid flows from passage 13 into the chamber 18 beneath piston 16. A buildup of pressure in chamber 18 raises piston 16, shaft 23, head 24 and mantle 25, relative to concave 3 which reduces the maximum discharge opening from the crushing chamber 26. As piston 16 moves upwardly, the cam surface 30 is moved upwardly and because of the slope of cam surface 30, the core 33 of the LVDT 32 slides inwardly and the LVDT produces an electrical output signal which is changed in proportion to the change in the position of core 33. This change in the electrical signal is indicated on dial 36 which may be calibrated to indicate the smaller maximum opening from chamber 26 for the particular elevated position of mantle achieved by such upward movement by piston 16. Venting fluid pressure out passage 13 from chamber 18, lowers piston 16, shaft 23, head 24 and mantle 25, relative to concave 3 and this increases the maximum discharge opening from the crushing chamber 26. As piston 16 moves downwardly, the cam surface pushes core 33 of the LVDT to slide outwardly through the bore 34 and the LVDT produces an electrical output signal which is changed in proportion to the position of core 33. This change in the electrical signal is indicated on dial 36 calibrated to indicate the larger maximum opening from chamber 26 for the new position of mantle 25 achieved by such downward movement of piston 16.

From the foregoing detailed description of the present invention, it has been shown how the objects of the invention have been attained in a preferred manner. However, modifications and equivalents of the disclosed concepts such as readily occur to those skilled in the art are intended to be included within the scope of this invention. Thus, the scope of this invention is intended to be limited solely by the scope of the claims such as are or may hereafter be appended hereto.

The embodiments of the invention in which I claim an exclusive property or privilege are defined as follows:

1. In a gyratory crusher having a lower frame and an upper frame, a vertical crusher .post assembly slidably supported by the lower frame, an overhanging concave ring horizontally supported in a fixed position within the upper frame above said post assembly, a crusher head mounted on top of said post assembly and disposed within the space defined by the concave ring, a vertically adjustable chamber defined by the lower frame and a bottom surface of the post assembly, and means for admitting fluid pressure to the chamber for supporting the lower end of said post assembly and crusher head to vary the opening defined between said concave ring and said crusher head, the improvement comprising: the post assembly having a tapered portion defining a cam surfacethat slopes vertically and inwardly from a portion of the post assembly in surface, to

surface contact with a portion of the lower frame; and a cam followingmember horizontally and slidably mounted in the lower frame with one end thereof projecting inwardly and engaging the cam surface while the other end of the member pro ects outwardly from the lower frame to indicate the vertical position of the post assembly relative to the frame and the crusher head relative to the concave ring.

2. In a gyratory crusher according to claim 1, the cam following memberbeing an extended movable core of a linear variable differential transformer connected to the lower frame and operative to provide an electrical output signal that indicates the position of the core relative to the lower frame when the core engages the cam surface, and indicates by such signal the position of the post assembly relative to the frame and the crusher head relative to the concave ring.

3. In a gyratory crusher according to claim 1, the tapered cam surface defining portion of the post assembly being sloped downward and inward from the said portion of the post assembly in surface to surface contact with the portion of the lower frame through which the cam following member projects, and the cam following member moves inwardly through the lower frame to contact the cam surface upon upward movement of the post assembly and the cam following member is pushed outwardly by the cam surface upon downward movement of the post assembly.

4. In a gyratory crusher according to claim 1 the post assembly including a piston and a shaft with the crusher head being mounted on the shaft over the piston, and the cam surface being defined by a tapered portion of the piston.

5. In a gyratory crusher according to claim 4 the piston having a downwardly pointed taper defining the cam surface with the cam following member moving inwardly through the lower frame to contact the cam surface upon upward movement of the piston and the cam following member being pushed outwardly through the lower frame by the cam surface upon downward movement of the piston.

6. A supporting and position indicating assembly for carrying a crushing head assembly of a gyratory crusher at selected vertically spaced levels relative to an outer concave ring, the supporting and position indicating assembly comprising: a cylinder, an end wall enclosing one end of said cylinder and having an oil admitting passage therethrough, a piston within the cylinder having an assembly carrying surface on a side of the piston opposite the side of the piston facing the end wall, the piston having a tapered portion defining a cam surface that slopes radially inward in a plane perpendicular to the end wall, and a cam following member parallel to the end wall and slidably mounted in the cylinder with one end projecting inwardly and engaging the cam surface while the other end of the member projects outwardly of the cylinder to indicate the position the assembly carrying surface relative to the cylinder.

7. An assembly according to claim '6 in which the cam surface is sloped inwardly from the assembly carrying sideof the piston toward the side of the piston facing the end wall of the cylinder, and the cam following member moves inwardly through the cylinder to contact the cam surface of the piston upon movement of the piston away from the end wall of the cylinder and the cam following member is pushed outwardly through the cylinder by the piston cam surface upon movement of the piston toward the cylinder end wall.

8. An assembly according to claim 7 in which the cam following member is an extended movable core of a linear varia ble differential transformer connected to the cylinder and operative to provide an electrical output signal proportional to the position of the core engaging the cam surface and indicates by such signal the position of the piston relative to the cylinder and the level to which the piston has raised an assembly carried thereon. 

1. In a gyratory crusher having a lower frame and an upper frame, a vertical crusher post assembly slidably supported by the lower frame, an overhanging concave ring horizontally supported in a fixed position within the upper frame above said post assembly, a crusher head mounted on top of said post assembly and disposed within the space defined by the concave ring, a vertically adjustable chamber defined by the lower frame and a bottom surface of the post assembly, and means for admitting fluid pressure to the chamber for supporting the lower end of said post assembly and crusher head to vary the opening defined between said concave ring and said crusher head, the improvement comprising: the post assembly having a tapered portion defining a cam surface that slopes vertically and inwardly from a portion of the post assembly in surface to surface contact with a portion of the lower frame; and a cam following member horizontally and slidably mounted in the lower frame with one end thereof projecting inwardly and engaging the cam surface while the other end of the member projects outwardly from the lower frame to indicate the vertical position of the post assembly relative to the frame and the crusher head relative to the concave ring.
 2. In a gyratory crusher according to claim 1, the cam following member being an extended movable core of a linear variable differential transformer connected to the lower frame and operative to provide an electrical output signal that indicates the position of the core relative to the lower frame when the core engages the cam surface, and indicates by such signal the position of the post assembly relative to the frame and the crusher head relative to the concave ring.
 3. In a gyratory crusher according to claim 1, the tapered cam surface defining portion of the post assembly being sloped downward and inward from the said portion of the post assembly in surface to surface contact with the portion of the lower frame through which the cam following member projects, and the cam following member moves inwardly through the lower frame to contact the cam surface upon upward movement of the post assembly and the cam following member is pushed outwardly by the cam surface upon downward movement of the post assembly.
 4. In a gyratory crusher according to claim 1 the post assembly including a piston and a shaft with the crusher head being mounted on the shaft over the piston, and the cam surface being defined by a tapered portion of the piston.
 5. In a gyratory crusher according to claim 4 the piston having a downwardly pointed taper defining the cam surface with the cam following member moving inwardly through the lower frame to contact the cam surface upon upward movement of the piston and the cam following member being pushed outwardly through the lower frame by the cam surface upon downward movement of the piston.
 6. A supporting and position indicating assembly for carrying a crushing head assembly of a gyratory crusher at selected vertically spaced levels relative to an outer concave ring, the suppOrting and position indicating assembly comprising: a cylinder, an end wall enclosing one end of said cylinder and having an oil admitting passage therethrough, a piston within the cylinder having an assembly carrying surface on a side of the piston opposite the side of the piston facing the end wall, the piston having a tapered portion defining a cam surface that slopes radially inward in a plane perpendicular to the end wall, and a cam following member parallel to the end wall and slidably mounted in the cylinder with one end projecting inwardly and engaging the cam surface while the other end of the member projects outwardly of the cylinder to indicate the position the assembly carrying surface relative to the cylinder.
 7. An assembly according to claim 6 in which the cam surface is sloped inwardly from the assembly carrying side of the piston toward the side of the piston facing the end wall of the cylinder, and the cam following member moves inwardly through the cylinder to contact the cam surface of the piston upon movement of the piston away from the end wall of the cylinder and the cam following member is pushed outwardly through the cylinder by the piston cam surface upon movement of the piston toward the cylinder end wall.
 8. An assembly according to claim 7 in which the cam following member is an extended movable core of a linear variable differential transformer connected to the cylinder and operative to provide an electrical output signal proportional to the position of the core engaging the cam surface and indicates by such signal the position of the piston relative to the cylinder and the level to which the piston has raised an assembly carried thereon. 